Tachykinin is a general name for a group of neuropeptides, and there have been known substance P (hereinafter referred to as “SP”), neurokinin-A, and neurokinin-B in mammals. These peptides are known to exhibit a various kinds of biological activities by binding their corresponding receptors which exist in vivo (neurokinin-1, neurokinin-2, neurokinin-3). Among them, SP is one of those which have the longest history in the neuropeptides, and have been studied in detail. Its existence was confirmed in an extract of horse intestinal tube in 1931, and it was a peptide comprising 11 amino acids, whose structure was determined in 1971.
SP exists widely in central and peripheral nervous systems, and it has physiological activities such as vasodilative action, vascular permeability promoting action, smooth muscle contracting action, neuronal excitatory action, salivary action, diuretic action, immunological action, etc., as well as a function of neurotransmitter of the primary sensory neuron. Especially, it is known that SP released from the terminal of posterior horn of spinal cord upon pain impulse transfers pain information to the secondary sensory neuron, and that SP released from the peripheral terminal induces an inflammatory response via its receptors. From these facts, SP is considered to be involved in various diseases (for example, pain, inflammation, allergy, pollakiuria, urinary incontinence, respiratory disease, mental disorder, depression, anxiety, emesis, etc.), and also, SP is considered to be involved in Alzheimer-type dementia [Review: Physiological Reviews, vol. 73, pp. 229-308 (1993) (Non-Patent literature 1), Journal of Autonomic Pharmacology, vol. 13, pp. 23-93 (1993) (Non-Patent literature 2)].
[Non-Patent literature 1]
Physiological Reviews, vol. 73, pp. 229-308 (1993).
[Non-Patent literature 2]
Journal of Autonomic Pharmacology, vol. 13, pp. 23-93 (1993).